Immersed boundary-finite element model of fluid-structure interaction in the aortic root

It has long been recognized that aortic root elasticity helps to ensure efficient aortic valve closure, but our understanding of the functional importance of the elasticity and geometry of the aortic root continues to evolve as increasingly detailed in vivo imaging data become available. Herein, we describe fluid-structure interaction models of the aortic root, including the aortic valve leaflets, the sinuses of Valsalva, the aortic annulus, and the sinotubular junction, that employ a version of Peskin's immersed boundary (IB) method with a finite element (FE) description of the structural elasticity. We develop both an idealized model of the root with three-fold symmetry of the aortic sinuses and valve leaflets, and a more realistic model that accounts for the differences in the sizes of the left, right, and noncoronary sinuses and corresponding valve cusps. As in earlier work, we use fiber-based models of the valve leaflets, but this study extends earlier IB models of the aortic root by employing incompressible hyperelastic models of the mechanics of the sinuses and ascending aorta using a constitutive law fit to experimental data from human aortic root tissue. In vivo pressure loading is accounted for by a backwards displacement method that determines the unloaded configurations of the root models. Our models yield realistic cardiac output at physiological pressures, with low transvalvular pressure differences during forward flow, minimal regurgitation during valve closure, and realistic pressure loads when the valve is closed during diastole. Further, results from high-resolution computations demonstrate that IB models of the aortic valve are able to produce essentially grid-converged dynamics at practical grid spacings for the high-Reynolds number flows of the aortic root

Overweight, Obesity and Underweight Is Associated with Adverse Psychosocial and Physical Health Outcomes among 7-Year-Old Children: The 'Be Active, Eat Right' Study

Background:Limited studies have reported on associations between overweight, and physical and psychosocial health outcomes among younger children. This study evaluates associations between overweight, obesity and underweight in 5-year-old children, and parent-reported health outcomes at age 7 years.Methods:Data were used from the 'Be active, eat right' study. Height and weight were measured at 5 and 7 years. Parents reported on child physical and psychosocial health outcomes (e.g. respiratory symptoms, general health, happiness, insecurity and adverse treatment). Regression models, adjusted for potential confounders, were fitted to predict health outcomes at age 7 years.Results:The baseline study sample consisted of 2,372 children mean age 5.8 (SD 0.4) years; 6.2% overweight, 1.6% obese and 15.0% underweight. Based on parent-report, overweight, obese and underweight children had an odds ratio (OR) of 5.70 (95% CI: 4.10 to 7.92), 35.34 (95% CI: 19.16; 65.17) and 1.39 (95% CI: 1.05 to 1.84), respectively, for being treated adversely compared to normal weight children. Compared to children with a low stable body mass index (BMI), parents of children with a high stable BMI reported their child to have an OR of 3.87 (95% CI: 1.75 to 8.54) for visiting the general practitioner once or more, an OR of 15.94 (95% CI: 10.75 to 23.64) for being treated adversely, and an OR of 16.35 (95% CI: 11.08 to 24.36) for feeling insecure.Conclusion:This study shows that overweight, obesity and underweight at 5 years of age is associated with more parent-reported adverse treatment of the child. Qualitative research examining underlying mechanisms is recommended. Healthcare providers should be aware of the possible adverse effects of childhood overweight and also relative underweight, and provide parents and children with appropriate counseling

Using formative research to develop the healthy eating component of the CHANGE! school-based curriculum intervention

Background: Childhood obesity is a significant public health concern. Many intervention studies have attempted to combat childhood obesity, often in the absence of formative or preparatory work. This study describes the healthy eating component of the formative phase of the Children’s Health Activity and Nutrition: Get Educated! (CHANGE!) project. The aim of the present study was to gather qualitative focus group and interview data regarding healthy eating particularly in relation to enabling and influencing factors, barriers and knowledge in children and adults (parents and teachers) from schools within the CHANGE! programme to provide populationspecific evidence to inform the subsequent intervention design. Methods: Semi-structured focus group interviews were conducted with children, parents and teachers across 11 primary schools in the Wigan borough of North West England. Sixty children (N = 24 boys), 33 parents (N = 4 male) and 10 teachers (N = 4 male) participated in the study. Interview questions were structured around the PRECEDE phases of the PRECEDE-PROCEED model. Interviews were transcribed verbatim and analysed using the pen-profiling technique. Results: The pen-profiles revealed that children’s knowledge of healthy eating was generally good, specifically many children were aware that fruit and vegetable consumption was ‘healthy’ (N = 46). Adults’ knowledge was also good, including restricting fatty foods, promoting fruit and vegetable intake, and maintaining a balanced diet. The important role parents play in children’s eating behaviours and food intake was evident. The emerging themes relating to barriers to healthy eating showed that external drivers such as advertising, the preferred sensory experience of “unhealthy” foods, and food being used as a reward may play a role in preventing healthy eating. Conclusions: Data suggest that; knowledge related to diet composition was not a barrier per se to healthy eating, and education showing how to translate knowledge into behavior or action is required. The key themes that emerged through the focus groups and pen-profiling data analysis technique will be used to inform and tailor the healthy eating component of the CHANGE! intervention study. Trial registration: Current Controlled Trials ISRCTN03863885 Keywords: Nutrition, Childhood obesity, Pen-profiles, Health, School

Fontes alternativas de energia para máquinas agrícolas.

Objetivando a reducao do consumo de oleo diesel na exploracao agricola brasileira, atualmente estimada em cerca de 3,8 bilhoes de litros por ano, a EMBRAPA iniciou programas de pesquisa e desenvolvimento a partir de 1981 em fontes alternativas de energia que pudessem apresentar viabilidades tecnicas e economicas na substituicao de oleo diesel em tratores, colhedeiras e conjuntos estacionarios de irrigacao e geracao de energia eletrica. Testes com tratores a alcool, com motores de ciclo Otto, empregando alcool hidratado produzido em microdestilarias tem demonstrado otima eficiencia e durabilidade. Tratores com motores do ciclo Diesel, trabalhando em sistema dual oleo diesel/gasogenio tem mostrado resultados satisfatorio para o emprego agricola. O emprego de gasogenio ou lenha e/ou carvao vegetal para acionar moto-bombas de irrigacao e conjuntos geradores indicam ser alternativas viaveis tecnica e economicamente, com a introducao de algumas inovacoes tecnologicas nos sistemas de limpeza dos gases. Testes estao sendo conduzidos com tratores providos de motores do ciclo Diesel em dupla alimentacao oleo diesel/alcool, com resultados altamente satisfatorios. Iniciam-se testes de uma frota experimental de tratores para utilizarem esteres etilicos de oleos vegetais em substituicao total ao oleo diesel

Detection by near-infrared spectroscopy of large lipid core plaques at culprit sites in patients with acute st-segment elevation myocardial infarction

ObjectivesThis study sought to describe near-infrared spectroscopy (NIRS) findings of culprit lesions in ST-segment elevation myocardial infarction (STEMI).BackgroundAlthough autopsy studies demonstrate that most STEMI are caused by rupture of pre-existing lipid core plaque (LCP), it has not been possible to identify LCP in vivo. A novel intracoronary NIRS catheter has made it possible to detect LCP in patients.MethodsWe performed NIRS within the culprit vessels of 20 patients with acute STEMI and compared the STEMI culprit findings to findings in nonculprit segments of the artery and to findings in autopsy control segments. Culprit and control segments were analyzed for the maximum lipid core burden index in a 4-mm length of artery (maxLCBI(4mm)).ResultsMaxLCBI(4mm) was 5.8-fold higher in STEMI culprit segments than in 87 nonculprit segments of the STEMI culprit vessel (median [interquartile range (IQR)]: 523 [445 to 821] vs. 90 [6 to 265]; p 400 distinguished STEMI culprit segments from specimens free of large LCP by histology (sensitivity: 85%, specificity: 98%).ConclusionsThe present study has demonstrated in vivo that a maxLCBI(4mm) >400, as detected by NIRS, is a signature of plaques causing STEMI.Ryan D. Madder, James A. Goldstein, Sean P. Madden, Rishi Puri, Kathy Wolski, Michael Hendricks, Stephen T. Sum, Annapoorna Kini, Samin Sharma, David Rizik, Emmanouil S. Brilakis, Kendrick A. Shunk, John Petersen, Giora Weisz, Renu Virmani, Stephen J. Nicholls, Akiko Maehara, Gary S. Mintz, Gregg W. Stone, James E. Mulle